Mechanical properties and sound velocity of gold copper (AuCu) II superlattice: 3D molecular dynamic (MD) simulation

Young’s modulus, yield stress and Poisson’s ratio are studied for different size and tem- perature. The temperature dependence of simulated Young’s modulus is quite similar to experimental results. Transverse sound velocity is estimated from the simulated elastic con- stants at each temperature. The dislocation speed reaches up to 75% of the transverse sound velocity. The dislocation speed decreases with increasing temperature linearly. The tempera- ture dependence of macroscopic deformation behavior and the possibility of the existence of supersonic dislocations are discussed. The transverse sound velocity and rigidity G is calcu- lated from Young’s modulus, Poisson’s ratio and density ρ which changes with temperature.